(Presumably, the need for a license is a matter of degree, given that our own bodies contain radioactive potassium-40, and given that the walls of most buildings contain the radioactive isotopes from the natural uranium-238 and thorium-232 decay chains).

Uranium and its decay products are both radioactive and toxic and, as they remain radioactive for hundreds of thousands of years, can cause irreparable damage to the environment and to generations of local communities.